Fuel-burner



J. R. SMITH. FUEL BURNER. APPLICATION FILED rams, 1918.

1,349,790. Patented Aug. 17, 1920 2 SHEETS-SHEET l- OOOOOOOO O0 I m [IvC J. R. SMITH. FUEL BURNER. APPL-ICATION mm FEB. 18, I916.

Patented Aug. 17, 1920 ax g 2 SHEETS-SHEET 2.

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of such ash and clinkers.

UNITED STATES 551cm OFFICE.

JAMES B. SMITH, 0F MECHANICSVILLE, NEW YORK.

FUEL-BURNER.

Specification of Letters Patent. Patented A 0; 1 7 1920 Applicationfiled February 18, 1918. Serial No. 217,949.

To all whom it may concern:

Be it known that I, JAMES R. SMITH, a citizen of the United States,residin at Mechanicsville, county of baratoga, btate of New York, haveinvented certain new and useful Improvements in Fuel-Burners, of whichthe following is a specification.

This invention relates to low grade fuel burners.

The object of the present invention is the provision of a novel airblast burner for heaters and steam boiler furnaces which will be adaptedfor use with low grade fuels such as coal dust, screenings, barley,birdseye and, in fact, all of the small grades of anthracite andbituminous coals, at half the cost of lump coal. I

In the burning of fine fuel, special pinhole plates or line slottedgrates are usually employed, and with the larger sizes of fuel the usualshaking or rocking grates are used. Both forms of grates are anexpensive item, if neglected, to replace. Furthermore, ordinary gratesand chimney draft cause undue fuel consumption, over-heating in theearly fall and spring and, despite regulation, air leakage and resultingdraft, causes great waste of fuel; furthermore, a very large percentageof combustiliile mate rial is shaken down into the ash pit when ordinarygrates are used.

My present improvements eliminate the foregoing effects and wastesincident to the use of ordinary grates and enable low grade fuels to beused with a maximum release of thermal units, minimumv of ash residue requiring removal, and lessening of the labor and attention required. i

In carrying out the invention, there is provided a fuel support which issealed from the ash pit except for means for dumping the ash andclinkers at those times when the fuel support requires the elimination()ne ormore burners or air blast boxes of novel construction andadaptation for the delivery of the air blast in a semilateral manner,say about 45 degrees, into the fuel, constitutes the means for supplyingoxygen to the fuel. The air is supplied under pressure to the burner orburners. The discharge openings in the burners change the pressure intoa volume of air which is directed upon the fuel support and reboundsorreacts in a general upward direction into the fuel bed, developingintense combustion and being disseminated throughout the fuel. When theblast is shut off the fire lies substantially dormant with noappreciable fuel consumption, but consumption begins when the blast isrenewed. The blast is automatically controlled, by preference, by thesteam pressure. For instance, an electrically driven blast fan is usedfor supplving the blast to the burner or burners, and the driving of thefan is under the control of an electric switch which is opened andclosed in response to the operation of a steam actuated regulatorsubject to steam derived from the boiler.

One or more dump openings are provided 111 the fuel support, normallyclosed by slidable dump-closures. hen said closures are opened, thewaste and clinkers fall into the ash pit. W hen the ash pit is cleaned,only the clinker will be thrown away, the other residue being again, fedinto the furnace for consun'iption.

The burner or blast box and the semi-lateral discharge of the air intothe fuel and its rebounding from the fuel support, and from the fuelitself, in iwardly through the fuel bed, constitute important featuresof the invention, including the transformation of the pressure withinthe burner, to volume, with reduced pressure, where the blast discharges into the fuel. The blast boxes serve to preheat the air beforeit is discharged into the fuel. I D

The embodiment of the invention hereinafter described and shown in theaccompanying drawings is susceptible of modification without departingfrom the essential principle thereof and it is to be considered. asillustrative, rather than restrictive, of the scope of the invention.

In the accompanying drawings,

Figure 1 is a vertical section showing the invention applied to a steamboiler Fig. 2, a front elevation, the boiler setting being broken awayand the shell of the blast fan being in section;

Fig. 3, a horizontal section or plan of the fuel support, burners, anddumps;

Fig. 4, a longitudinal section on the line a e of Fig. 3; I I

Fig. 5, a cross section on the line 55 of Fig. 3;

Fig. 6, a detail cross section of one of the burners; and

Fig. 7, a detail side elevation of one of the dumps.

holes 14 in the flanges 12.

The invention is illustrated in connection with a steam boiler but itmay be used on any type of furnace, heater, or fire box.

The boiler appears at l, the brick setting at 2, fire box doors at 3 andash pit doors at a. My invention is substituted for the usual grates andit directly supports the fuel.

The fuel support 5 is in the form of a horizontal tray having a sidewall 6 extending on the four sides thereof and being provided with legs7 which rest on the boiler foundation. The fuel support 5 fills thespace usually occupied by grates and is preferably sealed therein sothat there will be substantially no draft or air leakage from the ashpit 8 upwardly into the [ire box 9. Extending lengthwise of the .fuelsupport are one or more burners or blast boxes 10 which are preferablymade separate from the fuel support, as shown in Fig. 6, and fit snuglyinto longitudinal slots 11 and are provided with longitudinal flanges 12which are bolted at 13 to the fuel support 5, the bolts passing throughAs thus constructed and arranged, the burners or blast boxes have partof their height above the fuel support 5 and part therebelow. I do notlimit the burners or blast boxes to this arrangement and constructionnor to the rectangular or square cross sectional shape shown. The blastboxes or burners extend for as much of the length of the fuel support 5,from front to rear thereof, as may be desired; they are shown asextending from points somewhat back of the front end of the fuelsupport, to the extreme rear end'of said fuel support. The bu ners orblast boxes 10 are provided with semi-lateral discharge openings 15 onopposite sides thereof. As shown, these openings are continuouslongitudinal slots running from one end of the burner to the other endthereof, but they could be composed of a plurality of slots or openingsalthough the best results are obtained by having them substan tiallycontinuous so that a sheet of air will .be delivered from each side ofthe burner or box. In practice the openings or slots 15 aresubstantially at an angleof 45 degrees to the horizontal plane of thefuel support 5, but it is not essential to dispose them at that angle,the object being to have them direct the discharge of air in asemi-lateral direction, that is, at a point or angle between ahorizontal and a vertical plane, so that the air will be discharged in ageneral downward direction into the fuel and will rebound or reactupwardly into the fuel bed, thereby becoming thoroughly disseminatedthroughout the fuel and coming in contact with the fine particlesthereof.

I prefer to form the slots 15 by providing a removable cover or top 16for the burner 10, said cover having depending llangcs l? at its endswhich overlap and rest upon the ends of the box 1o at 18, Fig. l, thelongitudinal sides 19 of the cover being provided with inclined underfaces 2i), and the upper longitudinal edges of the sides of the box 10being beveled at 21. (ross ribs 16 on the under 'l'zn'e o i the coversupport it above the box 10, thus defining the slots 15. The slots 15are arranged at an angle of about 4-5 degrees to the fuel support 5. Thecovers 16 of the burners or boxcs Ill support the fuel which lies abovesaid boxes and prevent it from getting inside of the boxes. ll. will beunderstood. however. that the boxes 10 are buried in the fuel supportedby the fuel support 5. and that the boat from the fuel, radiated throughthe covers 16, prchoats the air in said boxes prior to its(lifir'iiill'g'l through the slots 15, thus increasing the eliiciency ofthe air blast. The covers [(3 are secured on the boxes l0 by bolts .10(liig. o) passing through holes in the cover and the bottom of the boxand having polygonal heads 10" seated in, and fitting, countersinlis 10so that said bolts will not turn. The bolts are packed with asbcsti'isIll where they pass through the bottoms of the boars 10 so that the nuts.10 will not be allowied by the excessive heat. (onscipicntly the nuts10 can be readily removed from the bolts whenever it is desired toren'iove the covers 16 as. for instance, when the covers burn out. Tosubstitute now covers 1b, it is only necessary to remove the nuts 10" asthe boxes 10 need not be disturbed. Being romovable, the covers 1Genable access to be had to the interiors of the boxes.

in air blast fan 22, which is suitably inclosed in a casing 23 outsidethe furnace, supplies the burners or boxes 10 with air, through a pipewhose branches 25 enter the bottoms of the boxes 10. The fan 22 isdriven by an electric motor 26 also contained within the casing 28. Anelectric switch of a well-known type controls the circuit leading to themotor 26, said switch being adapted to close and 0 ion by the followingcontrol. The switch comprises a rockable switch arm 27 mounted on apivot 27 and. adapted to be quickly opened or closed by a. flop overweighted lever 27" which is adapted to be moved past vertical positionto the right or left, Fig. 2. by an arm 27, also mounted, on pivot 27.The switch arm 27, lever 27, and arm 2T are loosely mounted in relationto each other on pivot 27. lVhen the arm 27 has moved le ver 27* pastthe vertical position, the lever flops over by its own weight and opensor closes the switch arm 2?, as the case may be, holding the switch armin closed or open p0 sition until a reverse movement of arm 27 occurs. Asteam-actuatcd regulator 28, deriving steam from the boiler by pipe 251,is

'ill

connected to the arm E27 by a chain 30 from which is suspended a weight31. The arm 27 is thus positively moved up or down, according as thesteam pressure rises or falls. The regulator 29 may be set to operate atany desired pressure. When that pressure is reached, the regulator leverpulls upon the chain 30 and opens the switch. When the pressure falls,the weight 31 closes the switch. The motor 26 is thus started when thepressure falls and stopped when it rises beyond the predetermined point.Consequently when the pressure is below the predetermined point, the airblown into the burners 10 is delivered in volume, at reduced pressure,through the slots 15, thus causing the fuel to burn and the pressure torise until the predetermined point is reached, whereupon the switch isopened and the blast stops. When there is no blast, the fire issubstantially dormant and little or no fuel consumption takes placeuntil the blast is resumed.

At the front ends of the burners are open frames 32 constituting clinkerand ash dumps. These have flanges .33 fastened at an to the support 5and are provided with inclined lower edges 35. Angle-iron guides 36which are fastened to the sides of the frames 32 at 37 extend forwardlyfrom the frames toward the ash pit doors 4. Slidable on the horizontalparts of the angle-iron guides 36 are closures 38 which have inclinedupper faces 39 adapted to wedge snugly against the inclined edges toeffect a tight closure of the frames 32. Pull rods 40 connected to theclosures 38 enable the latter to be opened or closed, on opening the ashpit doors 4.

llinkers and ash residue can be drawn forward on the fuel support 5 anddropped through the frames 32 into the ash pit. The clinkers may beremoved but as the ash residue contains unconsumed fuel, it may be againthrown on the fuel bed for consumption.

WVhat I claim is:

1. A fuel burner embodying the combination of a sealed fuel support, andan air blast feeder having means for discharging the air from pointsabove the fuel support in a general downward direction into the fuel andonto the fuel support to cause reboulnding of the air upwardly throughthe fue 2. A. fuel burner embodying the combination of a sealed fuelsupport, and an air blast box whose walls rise from the fuel support andare provided with openings located above the fuel support arranged fordischarging the air in a general downward direction into the fuel andonto the fuel support to cause rebounding of the air upwardly throughthe fuel.

3. A fuel burner embodying the combination of a sealed fuel support, andan air blast box having a top or cover and Walls which rise from thefuel support and are pro vided with openings located above the fuelsupport arranged for discharging the air in a generaldownward directioninto the fuel and onto the fuel. support to cause rebounding of the airupwardly through the fuel, and means for discharging air under pressureupwardly into the box and against the cover thereof.

In testimony whereof, I hereunto afiix my signature.

JAMES B. SMITH.

